1. Field of the Invention
The present invention relates to an incisor block. More particularly, the present invention relates to an incisor block with a removable cap that allows quick and easy placement of the incisor block on the maxillary anterior teeth.
2. Description of the Related Art
Decreasing deep anterior overbites is a problem often faced by orthodontic practitioners. Deep anterior overbites can be reduced to an ideal relation by extruding the posterior teeth toward one another. After sufficient extrusion, the posterior and anterior teeth occlude to form a "level" bite and the overbite can be reduced to 1 mm which is thought to be most desirable by many practitioners.
It is well known that individuals can exert significant pressure on the posterior grinding teeth but can exert relatively little pressure on the anterior teeth, particularly the incisors. The effect of this trait is to make it more difficult to extrude the posterior teeth to accomplish a level bite.
Practitioners face another problem with patients having excessive overbite ("deep bite patients") in that orthodontic braces on the facial surface of the lower teeth are often knocked off by the biting forces of the patient. This is because occlusion is done on the braces rather than with the maxillary teeth.
Hoffman, U.S. Pat. No. 4,480,994 describes an orthodontic occlusion prevention system in which a plate of material is positioned over selected maxillary anterior teeth. The plate prevents occlusion between the upper and lower posterior teeth. The plate is anchored by connection to sheaths that are connected to molar jackets. The difficulty with this system is that it involves a complicated support structure, is relatively large and cumbersome and, in this age of appearances, is readily noticeable in the mouth of the wearer.
Chorbajian in U.S. Pat. No. 4,419,992 describes a two layer occlusal splint in which a soft resilient layer is molded to conform to the posterior surface of the maxillary anterior tooth. The second layer is a hard acrylic resin mounted on the first layer. The hard resin is designed so that several lower teeth strike the splint at the same time, thereby equalizing and minimizing the pressure on the lower teeth. The splint is resiliently retained on the upper teeth by a snap fit. This splint is said to alleviate tempro-mandibular joint dysfunction. Because the splint extends around to the exterior surface of the anterior teeth, the splint is readily noticeable in the wearers mouth.
A recently developed innovation involves cementing pieces of acrylic on the lingual surfaces of at least two maxillary anterior teeth. These pieces of acrylic are not noticeable in the wearers mouth. Placement of these acrylic pieces can be a very challenging clinical procedure due to several factors.
The first factor is that the lingual surfaces of most maxillary incisors have very little anatomy to facilitate bonding the appliance without the appliance moving during the bonding procedure or during flash cleanup. The second factor is that the retro-inclination of the maxillary anterior teeth confronted in a typical Class II division 2 malocclusion where deep bites are almost always present presents difficulty for the practitioner to gain access and visibility.
An incisor block should be capable of being precisely formed and then precisely positioned within the mouth. Ideally, the form can be made on a mold of the teeth and the block can be formed prior to actually working in the patients mouth. The block should be formed to limit overbite to approximately 1 mm; an overbite which is considered ideal to most practitioners. Finally, the device should be capable of being rapidly and positively positioned within the mouth. In this way, adhesive, cement or other types of bonding agents can be applied to the incisor block before insertion. After the block is precisely inserted in the correct position, the block must be capable of being easily held in position while the adhesive cures.